The present invention relates to an apparatus for determining the dimensions of a package or object moving along a conveyor, and more particularly, to an apparatus for estimating the length, width and height of an object regardless of the objects orientation on the conveyor.
In many industries, it is often necessary to determine the volume of an object or package for a variety of reasons, such as calculating shipping costs, which can be based upon the volume and/or weight of an object. This information can also be used in connection with planning loads for a delivery vehicle based on the available packing volume. It is desirable to be able to make such measurements automatically while the object or package is being transported along a surface, such as a conveyor surface, in order to provide for high throughput of the objects or packages. The need for efficiency in handling packages has become more apparent based on the increase in shipping for e-commerce businesses.
One known system utilizes a laser scanner in connection with a CCD reader in order to determine the volume of an object. However, the system has not proven reliable in use. Additionally, several of the known arrangements may introduce large errors into the calculation of the object dimensions which can result in undercharging or overcharging of shipping fees as well as additional problems in planning loads.
It would be desirable to provide a fast and accurate system for determining the overall dimensions of an object traveling on a conveyor. It would also be desirable to be able to provide information on the object orientation and position on the conveyor. This information can be utilized by label and/or bar code scanners in order to properly direct and focus the scanners and image sensors on the object.
Briefly stated, the present invention is directed to an apparatus for determining the measurements of an object moving along a conveyor path having a support surface. The apparatus includes an object detector located along the conveyor path which is adapted to detect the leading edge of the object and generate a leading edge signal. An object speed detector is located along the conveyor path and is adapted to generate an object speed signal. A light source is located above the conveyor path and generates a light beam having a sharp edge which extends across the support surface in a direction transverse to a direction of movement of the object to define a light beam intersect path on the support surface. The light beam is arranged at a fixed angle of incidence of less than 90xc2x0 relative to the support surface. An image sensor is located above the support surface and includes a line of sight generally normal to the support surface which is directed through a lens located between the image sensor and the support surface to focus a reflected image of the light beam intersect path projected on the support surface onto the image sensor such that the image sensor detects the light beam intersect path on the support surface only in areas not obstructed by the object and generates a negative image profile signal. A processor is provided in communication with the object detector, the object speed sensor and the image sensor which receives the leading edge signal, the object speed signal and the negative image profile signal and calculates an approximate object size.
In another aspect, the present invention provides a method of determining measurements of an object moving along a conveyor path having a support surface. The method includes:
(a) projecting a light beam having a sharp edge from a light source aimed at a fixed angle of incidence transversely across the support surface to define a light beam intersect path on the support surface;
(b) moving the object along the support surface;
(c) sensing a leading edge of the object at a fixed point along the conveyor path with a first sensor and generating a leading edge signal;
(d) detecting the speed of the object with an object speed detector and generating an object speed signal;
(e) detecting an initial blockage of the light beam intersect path on the support surface by the object and generating a height timing signal;
(f) observing a reflected image of the light beam intersect path projected on the support surface in areas not obstructed by the object as the object moves along the support surface with an image sensor having a line of sight generally normal to the object support surface and generating a negative image profile signal;
(g) transmitting the leading edge signal, the object speed signal, the height determination signal, and the negative image profile signal to a processor; and
(h) calculating the object dimensions in the processor using the signals received from step (g).